This invention relates to a combination weigher, and particularly to a combination weighing device useful in preparing packs of articles whose individual weights do not vary from each other by more than a predetermined range.
In the case of producing packs or packages each containing plurality of articles having a total weight within an allowable range, it is well known that a so-called combination weigher is effectively used for this purpose. Such combination weigher is disclosed, for example, in U.S. Pat. No. 4,336,852. The combination weigher is provided with a plurality of mutually independent weighing units and is adapted to weigh one or more articles by each unit at the same time, combine the resultant weight indicative signals from the weigh units in various fashions, select from the resultant combinations a combination having a total weight within a predetermined range, and deliver the articles from the corresponding weigh units. Although such combination weigher is conveniently used for producing a number of packs of the same weight of content, the individual articles contained in each pack are not always uniform in their respective weights, and in fact substantial inequality or variance is unavoidable therein.
However, in the case, for example, of small fishes or culets of fish or meat prepared for cooking, it is often more desirable that the number of individual pieces in each pack be constants, and that the weight or size of each piece in the pack be as uniform as possible, rather than have the total weight of each pack be uniform. It is impossible to prepare such packs by the known combination weigher as disclosed above (unless the articles to be weighed are previously sorted as uniform in their individual weights).